Question: $ { \left[\begin{array}{r}{-1} \\ {2} \\ {0}\end{array}\right]+\left[\begin{array}{r}{-1} \\ {-1} \\ {-2}\end{array}\right] = {?} } $
Solution: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{r}{-1}+{-1} \\ {2}+{-1} \\ {0}+{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{-2} \\ {1} \\ {-2}\end{array}\right]}$